JPH0688025A - Diluent for silicone coating material - Google Patents

Abstract

PURPOSE:To obtain a diluent for silicone coating material excellent in the effect of imparting slipperiness to a coated surface and uniform applicability by incorporating a low-molecular-weight siloxane selected from the group consisting of a specified cyclic siloxane and a specified acyclic siloxane. CONSTITUTION:At least one low-molecular-weight siloxane selected from the group consisting of a cyclic siloxane of formula I (wherein R<1> is H or a monovalent hydrocarbon group; and m is 3-8) and an acyclic siloxane of formula II (wherein R<1> is as defined above; and n is 1-6) is incorporated to obtain the diluent. This diluent can give a silicone coating material which can form a cured film excellent in slipperiness and the evenness of film thickness and substantially free from nonuniformity of drying and cissing. This diluent scarcely affects the global environments. When the skin is coated with a silicone coating material containing this diluent, the formed coating film is effective in alleviating a pain during sticking a metallic hypodermic needle in the skin and to reduce the resistance of cutting the skin with a cutter, a surgical knife or scissors to allow good cut with slight force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a diluent for a silicone coating agent, which gives a silicone coating agent excellent in the effect of imparting slipperiness to a coated surface and uniform coating property.

[0002]

2. Description of the Related Art Conventionally, an organic silicone-containing polymer has been widely used as a silicone coating agent for the purpose of forming a film on the surface of a substance to improve slipperiness.
As a conventional technique for this silicone coating agent, Japanese Patent Publication No. 46-3627 discloses that a metal surface of a razor blade, a hypodermic needle, scissors, a scalpel, etc. is coated with aminoalkylsiloxane and dimethylsiloxane. Apply silicone coating agent diluted with organic solvent
It has been described that curing can improve the durability of surface slippage in metal products. Furthermore,
62-52796 discloses a silicone coating agent prepared by diluting a reaction product of an amino group-containing silane and an epoxy group-containing silane and a reaction product of polydiorganosiloxane on an inert solvent on the surface of metal, wood or plastic. Application /
It is described that by curing, the slipperiness of the coated surface can be improved.

Further, the above-mentioned conventional silicone coating agents are marketed in a state where the silicone component is diluted with an organic solvent such as toluene, isopropanol, or chlorofluorocarbon to about 30 to 50% (% by weight, the same applies hereinafter), and further used at the time of use. n −
An organic solvent such as hexane, freon, isopropanol, and chlorinated hydrocarbon is added to dilute the silicone component to about 2 to 5%, and the product is applied and cured to form a film.

However, even if the silicone component is improved as described above or used after being diluted with the above-mentioned organic solvent, the conventional silicone coating agent does not have a sufficient effect of imparting slipperiness to the coated surface or a uniform film is formed. There is a drawback that it is difficult to form a thick film, and uneven drying and cissing phenomenon are likely to occur, and improvement of both of these drawbacks has been desired.

For the purpose of improving this, a mixed solution of methylene chloride and methanol is used as a diluting solvent.
As disclosed in Japanese Patent No. 2377, chlorinated hydrocarbons such as methylene chloride may lead to ozone layer depletion similarly to CFCs, and their use is not preferable from the viewpoint of the global environment.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is excellent in the effect of imparting slipperiness to the coating surface, is excellent in uniform coating property, and is also preferable in environmental hygiene. It is an object to provide a diluent for a silicone coating agent that provides a coating agent.

[0007]

Means for Solving the Problems As a result of intensive studies to achieve the above object, the present inventors have found that when a specific low molecular weight liquid silicone is used as a diluent for a silicone coating agent, It was found that a cured film having excellent slipperiness on the surface, a uniform film thickness, and almost no unevenness in drying and repelling phenomenon can be obtained, and the present invention has been completed.

That is, the diluent for silicone coating agent of the present invention has the general formula 3

[0009]

[Chemical 3] (In the formula, R ¹ represents a hydrogen atom or a monovalent hydrocarbon group, m
Represents an integer of 3 to 8),
General formula 4

[0010]

[Chemical 4] (In the formula, R ¹ represents a hydrogen atom or a monovalent hydrocarbon group,
Is a linear siloxane represented by 0 or an integer of 1 to 6) and one or more low molecular weight siloxanes selected from the group consisting of:

Here, R ¹ represents hydrogen atoms which are the same or different from each other or a monovalent hydrocarbon group, and examples of the hydrocarbon group include an alkyl group such as a methyl group, an ethyl group and a propyl group, a vinyl group and an allyl group. Examples thereof include aryl groups such as alkenyl groups, phenyl groups, and tolyl groups. Of these, a hydrogen atom or a methyl group is preferable from the viewpoint of ease of synthesis and availability of raw materials.

The number m of repeating units of the cyclic siloxane represented by the general formula 3 is an integer of 3-8. When it is 9 or more, the volatilization rate is slow and removal after forming the coating film is difficult, which is not suitable. From the viewpoint of volatilization rate and ease of synthesis, m is preferably an integer of 3-6.

The number n of repeating units of the chain siloxane represented by the general formula 4 is 0 or an integer of 1-6.
In the case of 7 or more, as in the case of the cyclic siloxane,
The volatilization rate is slow, and removal after coating film formation is difficult, which is not suitable. From the volatilization rate, n is preferably 0 or an integer of 1 to 3.

The diluent for silicone coating agent of the present invention is used so that the silicone active ingredient of the silicone coating agent is diluted to 0.1 to 80% by weight. 0.1
If it is less than wt%, it becomes difficult to form a coating film having a sufficient film thickness, and if it exceeds 80 wt%, it becomes difficult to obtain a coating film having a uniform film thickness. Preferably 1 to
Used to be diluted to 20% by weight.

In this case, the silicone component of the silicone coating agent is not particularly limited and various silicone components can be used. For example, the aminoalkyl siloxane and the dimethyl siloxane described in Japanese Patent Publication No. 46-3627 can be used. Copolymer, reaction product of polydiorganosiloxane with reaction product of amino group-containing silane and epoxy group-containing silane described in JP-B-62-52796, Japanese Patent Publication
Examples thereof include a composition comprising an alkenyl group-containing polyorganosiloxane, a polyorganohydrogensiloxane for crosslinking and chain extension, and a non-reactive organopolysiloxane described in JP-A-3-46499.

Among these, a copolymer of aminoalkylsiloxane and dimethylsiloxane, a reaction product of a reaction product of an amino group-containing silane and an epoxy group-containing silane and a polydiorganosiloxane is preferably used, and the latter reaction is particularly preferable. The product is preferably used. As the former example, the following are specifically exemplified. (1) General formula

[0017]

[Chemical 5] (Here, X represents a hydroxyl group or a hydrolyzable group, R ² represents a hydrogen atom or a monovalent hydrocarbon group, and p represents an integer of 1 to 10,000.)
100 parts by weight of the polydiorganosiloxane represented by and (2) the general formula

[0018]

Embedded image Q ¹ ₂ N—R ³ —Si R ⁴ _q Y _3-q (wherein Q ¹ is a hydrogen atom, a methyl group or —CH ₂ CH ₂
NH ₂ and R ³ are divalent hydrocarbon groups, R ⁴ is a hydrogen atom or
Monovalent hydrocarbon group, Y is hydroxyl group or hydrolyzable group, and q is
A silicone coating agent comprising an amino group-containing polysiloxane as a main component obtained by reacting and polymerizing 1 to 40 parts by weight of an amino group-containing silane represented by 0 or an integer of 1 to 2).

Examples of the monovalent hydrocarbon group for R ² and R ⁴ include the same substituents as for R ¹ . Also R ³ 2
The valent hydrocarbon _{group, -CH 2 -, - CH 2} CH 2
_{-, - CH 2 CH 2 CH} 2 -, - CH 2 CH 2 CH 2 C
H ₂ − and the like are exemplified. As the hydrolyzable group of X and Y, an alkoxy group such as a methoxy group, an ethoxy group, a propoxy group; an alkenyloxy group such as a propenoxy group;
Acyloxy group such as acetoxy group, benzoxyl group; Organooxime group such as acetone oxime group, butanone oxime group, Organoaminoxy group such as dimethylaminoxy group, diethylaminoxy group; Dimethylamino group, diethylamino group, cyclohexylamino group, etc. Organoamino group; Organoamide groups such as N-methylacetamide group and the like are exemplified. It is represented by the above general formula 5.
(1) As the polydiorganosiloxane,

[0020]

[Chemical 7] Are exemplified. Here, p is an integer of 1 to 10,000, preferably 5 to 6,000, and particularly the viscosity at 25 ° C.
It is preferably 50 to 100,000 cSt.

The amino group-containing silane (2) represented by the general formula 6 is γ-aminopropyltriethoxysilane, γ-aminopropylmethyldiethoxysilane, N
-(Β-aminoethyl) aminomethyltrimethoxysilane, γ- (N- (β-aminoethyl) amino) propyltrimethoxysilane, γ- (N- (β-aminoethyl)
Amino) propylmethyldimethoxysilane, N- (β-
Aminoethyl) aminomethyltributoxysilane, γ-
(N- (β- (N- (β-aminoethyl) amino) ethyl) amino) propyltrimethoxysilane and the like are exemplified.

The (2) amino group-containing silane is used in an amount of 1 to 40 parts by weight based on 100 parts by weight of the (1) polydiorganosiloxane represented by the general formula 5. If it is less than 1 part by weight, it is difficult to obtain good slipperiness and adhesion to the substrate of the coating film obtained, and if it is more than 40 parts by weight, it becomes difficult to obtain good durability.

The polymerization reaction of (1) polysiloxane and (2) amino group-containing silane can be obtained, for example, by mixing both and heating and stirring using a catalyst and a solvent if necessary. As the catalyst, a catalyst for hydrolysis / condensation reaction, a catalyst for addition reaction, or the like can be appropriately selected depending on the kind of the functional group of the raw material.

A desired degree of polymerization can be obtained by controlling the reaction time of the polymerization reaction, the reaction temperature and the like.

Among the silicone active ingredients of the above-mentioned preferred silicone coating agent, the latter are specifically exemplified as follows. (3) 100 parts by weight of polydiorganosiloxane having at least one silanol group in one molecule, and (4) (a) the amino group-containing silane represented by the general formula 6 and (b) the general formula 8

[0026]

Embedded image Q ² —R ⁵ —Si R ⁶ _r Z _3-r (wherein Q ² is a glycidoxy group or an epoxycyclohexyl group, R ⁵ is a divalent hydrocarbon group, R ⁶ is a hydrogen atom or
Monovalent hydrocarbon group, Z is hydroxyl group or hydrolyzable group, r is
A silicone coating agent containing 0.1 to 20 parts by weight of a reaction product with an epoxy group-containing silane represented by 0 or 1 to 2) as a main component.

Here, the divalent hydrocarbon group of R ⁵ is as follows:
Examples are the same groups as R ³ . Further, the monovalent hydrocarbon group for R ⁶ is exemplified by the same substituents as R ¹ . Examples of the hydrolyzable group of Z include the same groups as X.

The (3) polydiorganosiloxane having at least a monovalent silanol group in one molecule is a siloxane exemplified by the above formula (5), one end of which is blocked with a silanol group or a hydrolyzable group, Examples thereof include polydiorganosiloxane whose ends are closed with trimethylsilyl groups. This siloxane has a viscosity of 20 to 1,00 at 25 ° C.
The one used is 0,000 cSt, preferably 100-100,000 cSt.

Examples of the (a) amino group-containing silane include those described in the general formula (6). Further, as the (b) epoxy group-containing silane represented by the general formula 8,
γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, β- (3,
4-epoxycyclohexyl) ethyltrimethoxysilane, β- (3,4-epoxycyclohexyl) ethylmethyldimethoxysilane, β- (3,4-epoxycyclohexyl) ethyltriethoxysilane, β- (3,4-epoxycyclohexyl) Examples include ethylmethyldiethoxysilane.

The (4) reaction product of the amino group-containing silane and the epoxy group-containing silane is (b) epoxy group-containing silane 0.5 to 3.0 mol, preferably 0.75 to 1.5 mol, based on 1 mol of the amino group-containing silane. In addition, it is obtained by reacting by heating with stirring. 0.1 to 20 of this (4) reactant
By mixing 1 part by weight, preferably 1 to 10 parts by weight, with 100 parts by weight of (3) polydiorganosiloxane containing a silanol group, a solvent is used if necessary, and the mixture is heated and reacted to give a silicone coating agent. Is obtained.

Various organic solvents can be used in the silicone coating agent of the present invention as long as the characteristics of the present invention are not impaired. Such organic solvents include toluene, xylene, cyclohexane, n-hexane, n-heptane, naphtha, mineral spirits, hydrocarbon solvents such as petroleum benzine, chloroform, carbon tetrachloride, trichloroethylene, perchlorethylene, 1, 1,1-
Halogenated hydrocarbon solvent such as trichloroethane,
Ethyl ether, tetrahydrofuran, ether solvents such as ethylene glycol diethyl ether, ethyl acetate, butyl acetate, ester solvents such as amyl acetate, ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone, methanol, ethanol, propyl alcohol, An alcohol solvent such as isopropyl alcohol may be used.

[0032]

EXAMPLES The present invention will be specifically described with reference to the following examples. Here, in the examples, "part" means "part by weight", "%" means "% by weight", and the viscosity shows a value at 25 ° C.

Preparation Example 1 Equimolar amounts of γ-aminopropyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane were adjusted to 80 to 100.
0.5 part of the reaction product obtained by reacting for 3 hours at ℃, 20 parts of polydimethylsiloxane with a viscosity of 20,000 cSt, both ends blocked with silanol groups, one end blocked with silanol groups, the other end blocked with trimethylsilyl groups. A mixture of 19.5 parts of polydimethylsiloxane having a viscosity of 1500 cSt and 60 parts of toluene was reacted at 80 ° C. for 8 hours to obtain a colorless transparent solution (coating agent A).

Examples 1 to 3 and Comparative Examples 1 to 4 The silicone coating agent A obtained in Preparation Example 1 was treated with the diluents of Examples 1 to 3 and Comparative Examples 1 to 4 shown in Table 1 to obtain silicone effect. The ingredients were diluted to 3%.

Next, the SUS plate with the cleaned surface (width
The above diluting solution was flow-coated on 70 mm × length 150 mm × thickness 0.5 mm), and then dried and cured at room temperature for 24 hours. A plate without coating was used as a reference example. The dynamic friction coefficient of the obtained coating film surface was measured under the following conditions, and the surface state of the coating film was visually observed and evaluated according to the following criteria. The results are shown in Table 1.

Dynamic Friction Coefficient Measurement Conditions Contact tip ... SUS, load ... 80 g, speed ... 20 mm / min,
Temperature… 25 ℃, Humidity… 50% RH.

Evaluation Criteria for Surface State of Coating Film Thickness: ◎: uniform, ○: almost uniform, Δ: slightly uneven,
X: Non-uniform.

[0038]

[Table 1]

[0039]

The diluent for a silicone coating agent of the present invention is excellent in slipperiness, has a uniform film thickness, and has uniform dryness.
A silicone coating agent capable of forming a cured film with almost no cissing phenomenon. Further, the diluent for a silicone coating agent of the present invention has little effect on the global environment. Therefore, if the diluent of the present invention is used for silicone coating, the pain sensation at the time of piercing a metal injection needle can be greatly reduced. With regard to cutters, knives, and scissors, the resistance at the time of cutting is reduced, and the effect of cutting well with a light force is given.

The diluent for silicone coating agent of the present invention includes coats such as the above-mentioned injection needles, cutters, scalpels, scissors, razors and knives, as well as tableware forks, sewing needles, zipper, stapler needles, combs, Coat for improving slipperiness of cards, tickets, coins, etc.,
Further, it is also preferably used for bottle coat, plastic coat, wood coat and the like.

Claims (3)

[Claims] 1. A general formula 1 (In the formula, R ¹ represents a hydrogen atom or a monovalent hydrocarbon group, m
Represents an integer of 3 to 8),
General formula 2 (In the formula, R ¹ represents a hydrogen atom or a monovalent hydrocarbon group,
Is a linear siloxane represented by 0 or an integer of 1 to 6) and a low molecular weight siloxane selected from the group consisting of a linear siloxane and a diluent for a silicone coating agent. 2. The diluent for a silicone coating agent according to claim 1, wherein the silicone coating agent is a silicone coating agent that imparts slipperiness to the surface of a metal product. 3. The diluent for a silicone coating agent according to claim 1, wherein the silicone coating agent is a coating agent for an injection needle.